Feline biology is not the same as humans, so we need to look at their biology and at what nature reveals to us. Cats have a shorter gastrointestinal tract and it is very acidic. The acidic nature of cats’ short digestive tract makes them less susceptible to food bacteria. This means cats can eat raw food without the consequences we would have if we ate uncooked meats.
While cats’ digestive system is great for raw prey consumption, it is not so great at digesting carbohydrates. Cats do not produce a significant quantity of enzymes for digesting grain. Carbohydrates in processed cat food derived from grains, potatoes, legumes, rice, etc. may cause inflammatory conditions, diabetes, allergies, pancreatitis, diarrhea, chronic constipation, or irritable bowel syndrome among other things.
Cats also, don’t digest cooked protein very well either. This too can result in all forms of digestive discomfort such as irritable bowel syndrome, diarrhea, and constipation. Unfortunately, the methods used to make processed cat food ends up destroying nutrients, and changing the chemistry resulting in what some veterinarians are saying is carcinogenic for cats.
Not only is processed food difficult to digest, but it can also result in additional loss of nutrients because of cats’ inability to breakdown and synthesize the food. Sadly, many cats end up obese and malnourished.